Correlations of sleep disorders with severity of obstructive airway disease in mustard gas-injured patients

Nocturnal serum melatonin levels in sulfur mustard exposed patients with sleep disorders

BACKGROUND

Sulfur mustard (SM) exposure causes respiratory disorders, progressive deterioration in lung function and mortality in injured victims and poor sleep quality is one of the most common problems among SM-exposed patients. Since melatonin has a critical role in regulation of sleep and awareness, this study aimed to evaluate the serum melatonin levels in SM-injured subjects.

METHODS

A total of 30 SM-exposed male patients and 10 controls was evaluated. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI); daytime sleepiness was measured by the Epworth Sleepiness Scale (ESS), and the risk of obstructive sleep apnoea was determined by the STOP-Bang questionnaire. Polysomnography (PSG) and pulmonary function tests (PFTs) were also available. Nocturnal serum melatonin levels were measured using an ELISA kit.

RESULTS

The mean of PSQI, ESS and STOP-Bang scores in patients (11.76±3.56, 12.6±3.03 and 5.03±1.09, respectively) were significantly (p<0.01) higher than those in the controls (2.78±0.83, 4.69±1.15 and 1.18±0.82, respectively). PFTs also showed declined respiratory quality in SM-patients. There was a significant difference regarding the PSG results between patients and controls (p<0.01). The mean of nocturnal serum melatonin levels in patients (29.78±19.31 pg/mL) was significantly (p=0.005) lower than that in the controls (78.53±34.41 pg/mL).

CONCLUSIONS

Reduced nocturnal serum melatonin and respiratory disorders can be the reasons for poor sleep quality among these patients.

TRIAL REGISTRATION NUMBER

IRCT2015092924267N1, Pre-results.

Respiratory effects of sulfur mustard exposure, similarities and differences with asthma and COPD

CONTEXT

Previous research has found relationships between sulfur mustard (SM) toxicity and its adverse effects.

OBJECTIVE

SM is highly toxic to the respiratory system, leading to hacking cough, rhinorrheachest tightness, acute pharyngitis and laryngitis, chronic bronchitis and lung fibrosis. In this review, based on the scientific literature, we provide an updated summary of information on SM exposures and their differences with asthma and COPD.

METHOD

Information of this review was obtained by searching Medline/PubMed, ScienceDirect, Scopus, Google Scholar, ISI Web of Knowledge and Chemical Abstracts.

RESULTS

SM exposure can decrease pulmonary function tests (PFTs) values. In addition, inflammatory cell accumulation in the respiratory tract and increased expression of some pro-inflammatory cytokines including tumor necrosis factor-α (TNFα), IL-1a, IL-1β, and reactive oxygen radicals due to SM exposure have been shown. Matrix metalloproteinase (MMP) which degrade extracellular matrix proteins, contributing to inflammatory cell recruitment, tissue injury and fibrosis are also up-regulated in the lung after SM exposure. In the lung, SM exposure also can cause serious pathological changes including airway inflammation, parenchymal tissue destruction and airway obstruction which can lead to asthma or chronic obstructive pulmonary disease (COPD). Following SM poisoning, DNA damage, apoptosis and autophagy are observed in the lung along with the increased expression of activated caspases and DNA repair enzymes.

CONCLUSION

In the present article, respiratory symptoms, changes in PFTs, lung pathology and lung inflammation due to SM exposure and the similarities and differences between them and those observed in asthma and COPD were reviewed.